In the course of military conflicts, armed forces are increasingly challenged by hostile optical systems, in particular during non-conventional warfare which happens more and more often. The term “optical systems” in the meaning of the present invention shall designate systems that may be optically localized, for example hostile detection and aiming systems, and, above all, gunners, in particular snipers. There is a need for systems that allow to detect, localize and, as the case may be, also aim fire at such hostile optical systems or snipers, respectively.
U.S. Pat. No. 6,057,915 discloses an apparatus of the type specified at the outset which operates in two steps. In a first step, an area in a terrain is scanned by swiveling a mirror and by feeding the received light signals to a two-dimensional array being sensitive to infrared radiation. The array detects the firing of a projectile fired by a gunner on the basis of the heat dissipated by the projectile, and, thereupon, initiates the second step in such a situation. In the second step the trajectory of the projectile is followed by means of a laser radar via the swiveling of a mirror and, from the trajectory, the location is computed from which the projectile was fired, corresponding to the position of the gunner. The covered image of the aiming area is displayed on a screen of a personal computer.
This prior art system, therefore, has the disadvantage that the gunner must have fired at least one projectile, before he may be localized. Further, the apparatus is not handy and, due to all its components, may be used only as a stationary installation.
On the other hand, apparatuses are commercially available in which a large-area illumination of an aiming scene takes place by means of laser light with a concurrent observation of the illuminated aiming scene through a CCD-camera.
These apparatuses allow a passive observation of a terrain area and permit to detect, for example, laser light that is reflected from an aiming telescope of a gunner. However, these systems have a considerable weight of more than 30 kg and have a high energy consumption in excess of 200 W, so that such systems in practice may only be used stationary and only for short periods of time, given the high energy consumption, unless corresponding big and heavy energy sources are used.
International patent application disclosure document WO 03/102626 A discloses an apparatus for detecting optical and opto-electronic objects. The apparatus uses a laser light source having a one-dimensionally enlarged light exit in a vertical direction, and being directed onto an aiming area. A row of detectors being arranged vertically one above the other receives the light reflected from the aiming area. Further, a telescope-like optical observation system is provided.
This system, too, has the disadvantage that it is very heavy and not easy to operate.
U.S. Pat. No. 6,603,134 discloses an apparatus for military applications, which is intended to detect the presence of an enemy by optical means, and for neutralizing the enemy thereafter. Primarily, the apparatus is intended to destroy or at least render inoperable infrared measuring installations of an enemy by using correspondingly strong laser beams. The apparatus is intended to attack hostile objects, for example a hostile satellite which spies the home country, or which may likewise be a human or an animal eye. The object is defined as a retroreflector. The light beams emitted by an optical detection installation of the apparatus are retroreflected by the object and impinge as reflected light beams on a detector. For scanning a terrain area, the apparatus is swiveled by means of a scanning installation. Within the apparatus, the signal received by the detector and processed thereafter is fed to a so-called utilization system. This system controls the scanning installation, in order to follow a moving object. However, it may also be used to control a high energy laser gun which neutralizes the aimed object by means of a high energy laser beam. The apparatus does not provide a processing or a display of an image.
U.S. Pat. No. 4,112,300 discloses an apparatus for jamming or for destroying a hostile infrared installation. Within the apparatus an image of a hostile object is reflected into the field of vision of a telescope by processing the incoming light.
From general measuring technology so-called 2D- or 3D-scanners are known for measuring or surveying large rooms, tunnels or the like. These scanners use a laser beam which is emitted into a plane by means of a periodically swiveled or a rotating mirror. The light reflected from the illuminated environment is fed to a detector via the same mirror. Such a 3D-scanner is disclosed in German patent application disclosure document DE 44 12 044 A1.